How to simplify these conditions ? (engine model c program)

[Jason Singh]

#include <stdio.h>
#include <math.h>
#include <stdlib.h>

float enginerpm, torq;

torque()
      {
                    
                   
                         if (enginerpm <1500)
                         {
                         torq = (0.03*(enginerpm - 1000)) + 160;
                         }
                         else
                         {
                             if (enginerpm <2000)
                             {
                             torq = (0.02*(enginerpm - 1500)) + 175;
                             }
                             else
                             {
                                 if (enginerpm <2500)
                                 {
                                 torq = (0.02*(enginerpm - 2000)) + 185;
                                 }
                                 else
                                 {
                                     if (enginerpm <3000)
                                     {
                                     torq = (0.01*(enginerpm - 2500)) + 195;
                                     }
                                     else
                                     {
                                     if (enginerpm <3500)
                                     {
                                     torq = (0.01*(enginerpm - 3000)) + 200;
                                     }
                                     else
                                     {
                                         if (enginerpm <4000)
                                         {
                                        torq = (0.01*(enginerpm - 3500)) + 205;
                                         }
                                         else
                                         {
                                         if (enginerpm <4500)
                                         {
                                        torq = (0.01*(enginerpm - 4000)) + 210;
                                         }
                                         else  
                                               {
                                               torq = 215;
                                               }
                                         }
                                         }
                                         }
                                         }
                                         }
                                         }
                                        
}

[Salem]

Like

if ( ) {
} else if ( ) {
} else if ( ) {
} else if ( ) {
} else {
}

[Elysia]

Wrong section, methinks. There is a section for C, but this is the section for C++.

[Salem]

Moved

[quzah]

Grab a pen and paper and work out just what's happening there, and you can save yourself a bunch of those if checks.


Quzah.

[Jason Singh]

Any way in which I can remove some 'if' statements???

[Salem]

Well you could plot torque vs. rpm on a graph using your function (it should be 7 points connected by straight lines).

Parametric equation - Wikipedia, the free encyclopedia
Then define a parametric equation for a curve which best fits those points.

[quzah]

Well you could plot torque vs. rpm on a graph using your function (it should be 7 points connected by straight lines).

Parametric equation - Wikipedia, the free encyclopedia
Then define a parametric equation for a curve which best fits those points.

I don't know whether to laugh or cry after reading that. I might do a little of both.


Quzah.

[KCfromNC]

float torque(float enginerpm)
{
   struct
   {
      int rpm_limit;
      double multiplier;
      int adder;
   } torque_list[] = 
   {
      {1500, 0.03, 160 },
      {2000, 0.02, 175 },
      {2500, 0.02, 185 },
      {3000, 0.01, 195 },
      {3500, 0.01, 200 },
      {4000, 0.01, 205 },
      {4500, 0.01, 210 },
      {INT_MAX, 0.0, 215 }
   };

   int i;

   for (i = 0; torque_list[i].rpm_limit < enginerpm; i++)
   {
   }

   return (torque_list[i].multiplier * (enginerpm - (torque_list[i].rpm_limit - 500))) + torque_list[i].adder;
}

[Jason Singh]

Is this compiled in c im getting errors when I try to compile in c.
INT_MAX undeclared
initialiser element is not compatible at load time
ISO 90 forbids mixed declaration and code

[Salem]

You need #include <limits.h> for INT_MAX

[hk_mp5kpdw]

Is this compiled in c im getting errors when I try to compile in c.
INT_MAX undeclared
initialiser element is not compatible at load time
ISO 90 forbids mixed declaration and code

Did you #include <limits.h>?

[Jason Singh]

Now I get get error
[Linker error] undefined reference to `WinMain@16'
returned 1 exit status

[Jason Singh]

Im using
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include <limits.h>

[Salem]

> [Linker error] undefined reference to `WinMain@16'
Your IDE thinks you're creating a GUI program (which begins at WinMain), but you seem to be writing a console program, which begins at main.